This application claims the priority of German Application NO. 10005752-7, filed Feb. 9, 2000, the disclosure of which is expressly incorporated by reference herein.
The present invention relates to a guiding and stacking system having a removal transport system which has a first conveying device which is set up for receiving the sheet metal parts and which has a controllable driving device which defines the conveying speed of the removal transport system, having a distributing guide, which has a second conveying device which is set up for receiving the sheet metal parts and which has a controllable driving device which defines the conveying speed of the second conveying device, having at least two stacking transport systems which each have another conveying device which is set up for receiving the sheet metal parts and which each have a controllable driving device which defines the conveying speed of the respective guiding and stacking transport system the distributing guide at least temporarily being changeable into a first position in which it adjoins one of the guiding and stacking transport systems and the distributing guide at least temporarily being changeable into a second position in which it adjoins the other guiding and stacking transport system.
Press systems, particularly vehicle body presses, supply sheet metal parts corresponding to their working cycle that have to be removed in a sequenced manner. Even when manufacturing very large sheet metal parts, such as motor vehicle side walls, doors or other sheet metal parts, press working lines reach working rates of approximately 15 strokes per minute. The sheet metal parts, which are obtained synchronously, should be removed and transported away without any damage. In each case, this has to take place in a fail-safe manner so that the operation of the press system will not be hindered. A frequent requirement is that a failure of an automatic guiding and stacking system will not lead to a stoppage of the press system or another production device disposed on the input side. A manual removal of sheet metal parts, which may weigh approximately 50 kg and are delivered at a 4-second cycle, is not easily possible. A failure of an automatic guiding and stacking system therefore usually results in a stoppage of the production device disposed on the input side.
An object of the present invention is to provide a high availability guiding and stacking system for sheet metal parts.
This object has achieved by a guiding and stacking system for sheet metal parts in which the conveying devices of the guiding and stacking transport systems each have at least one section operating in the start/stop operation.
The guiding and stacking system has a removal transport device which receives parts delivered by a system disposed on the input side, such as sheet metal parts delivered by a press system, and supplies them to a distributing guide. The distributing guide services two or several connected guiding and stacking transport systems which are alternately supplied with sheet metal parts. As a result, each guiding and stacking transport system receives only a fraction (half or less) of all sheet metal parts received by the removal transport system.
Each guiding and stacking transport system transports the sheet metal parts to one stacking site respectively, at which the sheet metal parts are then removed and stacked, for example, on pallets. For this purpose, corresponding gripper devices can be used which remove the sheet metal parts from the stacking and removing transport system and deposit them on pallets. The sheet metal parts arrive on the guiding and stacking transport system at a lower consecutive frequency than that at which they are delivered by the system, such as the press system. As a result of the reduced frequency, they can, as required or in an emergency, also be removed and stacked manually, whereby, even in the event of a failure of the gripper devices, the operation of the press system disposed on the input side can be continued.
The guiding and stacking transport conveying device has at least one section which stops temporarily. This makes it possible for an automatic gripper device arranged on the output side as well as for personnel assisting at times to grip the sheet metal parts and to remove and deposit them in a sequenced manner. In connection with the distributing guide, which is connected on the input side and which reduces the number of the sheet metal parts arriving per time unit (i.e., frequency), it therefore becomes possible, also at a high working rate of the press system (15 strokes per minute) and relatively large and therefore also heavy sheet metal parts, to manually remove and stack as an auxiliary measure in order to be able to continue the operation of the press system in special situations. Thus, the overall availability as a whole is increased.
The removal conveying device, the guiding and stacking device and/or the distributing guide conveying device can each be constructed as a conveyer belt. This has the advantage that no adaptation to different sheet metal parts is required. Furthermore, a careful transport of the sheet metal parts is ensured which is independent of the position.
The removal conveying device and the guiding and stacking conveying device, that is, for example, the moving belts of the removal transport system and of the guiding and stacking transport system move preferably at least temporarily at the same speed. This speed preferably corresponds to the conveying speed of the distributing guide. Thereby a good transition of the sheet metal parts from the removal conveying device to the distributing guide and from the distributing guide to the removal and stacking conveying device is ensured.
While the distributing guide conveying device is preferably continuously driven, the removal conveying device runs, for example, in the start/stop operation and, only for the transfer of the sheet metal parts to the distributing guide, has the same transport speed as the distributing guide. The average moving speed of the removal conveying device, however, is lower during the start/stop operation than that of the distributing guide. The corresponding situation exists with respect to the average speed of the guiding and stacking conveying device which, for example, can have a uniform conveying speed and thus, on the whole, can be driven in the start/stop operation. The average speed of the guiding and stacking conveying device will than be lower than that of the distributing guide. This also applies when only a section of the guiding and stacking conveying device is driven in the start/stop operation. It may be sufficient, for example, to operate the end of the guiding and stacking conveying device which is situated away from the distributing guide in the start/stop operation in order to permit a sequenced removal of the sheet metal parts and not have to accelerate and decelerate the entire conveying device.
By distributing the parts flow to several guiding and stacking conveying devices by way of the distributing guide, the average speed of the guiding and stacking conveying device can be lower than that of the removal conveying device. The low average speed of the guiding and stacking conveying device facilitates the manual guiding and stacking as well as the automatic access by robots.
This also applies to a spatial separation of the stacking sites which should preferably take place, the guiding and stacking transport systems leading to these stacking sites.